/*
 * Alloy Analyzer
 * Copyright (c) 2002 Massachusetts Institute of Technology
 *
 * The Alloy Analyzer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * The Alloy Analyzer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with the Alloy Analyzer; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package alloy.ast;

/** Represents a let with a formula body. */

public class LetFormula extends AbstractFormula implements Formula, Let {

    private static final int LETDECLS_INDEX = 0;
    private static final int BODY_INDEX = 1;
    
    public LetFormula(Location location_, LetDecls letDecls_, Formula body_) {
        super(location_, letDecls_, body_);
    }

    public LetFormula(LetDecls letDecls_, Formula body_) {
        this(Location.UNKNOWN, letDecls_, body_);
    }

    /** get the formula of this. */
    public Formula getFormula() {
        return (Formula)getBody();
    }

    /** get the let decls of this. */
    public LetDecls getLetDecls() {
        return (LetDecls)childAt(LETDECLS_INDEX);
    }

    /** set the LetDecls of this */
    public void setLetDecls(LetDecls newChild_) {
        setChild(LETDECLS_INDEX, newChild_);
    }

    /** get the body of this. */
    public Node getBody() {
        return childAt(BODY_INDEX);
    }

    /** set the Body of this */
    public void setBody(Node newChild_) {
        setChild(BODY_INDEX, newChild_);
    }

    /**
     * accept an AST visitor
     * @param visitor_ the visitor
     */
    protected void acceptVisitor(ASTVisitor visitor_) {
        visitor_.visit(this);
    }

    /**
     * accept a returning AST visitor
     * @param visitor_ the visitor
     * @return the Object returned by the visitor
     */
    protected Object acceptReturnVisitor(ASTReturnVisitor visitor_) {
        return visitor_.visit(this);
    }

}
